{"product_id":"manley-chevrolet-big-block-exhaust-valve-kit-1-940in-head-dia-5-422in-o-a-length-0-3415in-stem-1","title":"Manley Chevrolet Big Block Exhaust Valve Kit - 1.940in Head Dia. 5.422in O\/A Length, 0.3415in Stem","description":"Manley Severe Duty® Valves deliver the ultimate in strength, reliability, and high-performance durability. Engineered for extreme gasoline engine temperatures, these valves are crafted from exclusive materials (XH-428 for exhaust and NK-844 for intake), offering unmatched tensile strength compared to competitive alloys. In fatigue testing at 40,000 psi and 1400°F, Manley exhaust valves endured 100 million cycles, while competitors failed after just 100,000, proving a 1,000× longer fatigue life. Each valve features chrome stems, hard tips, and swirl-polished underheads with fully machined combustion faces for superior airflow, efficiency, and wear resistance. Built for those who demand race-winning strength and precision, Manley Severe Duty® Valves set the industry standard for performance and endurance.","brand":"Manley Performance","offers":[{"title":"Default Title","offer_id":44027057602682,"sku":"MAN11803-8","price":431.79,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0771\/8703\/files\/639c017773af16048d25285e221903acL_331e50f9-7d1c-4938-8c1e-3cb0b9475609.jpg?v=1753883681","url":"https:\/\/store.gtrauto.ca\/products\/manley-chevrolet-big-block-exhaust-valve-kit-1-940in-head-dia-5-422in-o-a-length-0-3415in-stem-1","provider":"GTR Auto","version":"1.0","type":"link"}